Postfix SMTP Auth to Dovecot Not Working -- HELP!

Hello Everyone! First off, would love to say Thanks to everyone here at HowToForge! I have been a fan for a long time now and love the tutorials that are one here!

This is the first time I have ever encountered an issue that I have been unable to solve by using the Tutorials and postings in the forum.

Here is my issue.

I have followed a number of tutorials to get my CentOS 5.4 32-bit up and running with Postfix and Dovecot using MySQL for virtual users and domains. I have everything working flawlessly (receiving emails from outside sources to my virtual users and domains and sending emails from localhost out to outside domains) except for sending email from non-trusted (anything other than localhost is untrusted). I keep getting:

Here is the maillog output from start to finish of when sending an email from my Client Winblows Outlook client (user@local-example.com is my email account on the server which works when sent from a trusted network, and user@remote-example.com is the account on an outside provider i.e. gmail.com):

Also, I just wanted to point out, if I add my client IP address to the trusted networks I have no problem and can send/receive email without any issues so the problem must have to do with postfix doing the SASL to Dovecot.

If you use an SSH client such as PuTTY, you can copy & paste from the tutorial. This helps avoiding typos.

Click to expand...

Thanks. Actually I did use PuTTy. However, I was copying & pasting from several different tutorials (from CentOS, to Debian, to Ubuntu, etc) to get my setup up and running that somewhere along the line that particular line got edited and input incorrectly.

Hmm, maybe I should submit a tutorial on this this particular setup as they are hard to come by these days.

I noticed Falko that you used to use Dovecot previously but switched to Courier. Any particular reason for this? Is there features Courier provides that Dovecot does not? or is it because you found Courier easier to integrate into ISPConfig? (which is a great product by the way, I use it for a couple of my other virtual servers that I host end-user stuff on).